The electronics industry has experienced an ever increasing demand for smaller and faster electronic devices which are simultaneously able to support a greater number of increasingly complex and sophisticated functions. Accordingly, there is a continuing trend in the semiconductor industry to manufacture low-cost, high-performance, and low-power integrated circuits (ICs). Thus far these goals have been achieved in large part by scaling down semiconductor IC dimensions (e.g., minimum feature size) and thereby improving production efficiency and lowering associated costs. However, such scaling has also introduced increased complexity to the semiconductor manufacturing process. Thus, the realization of continued advances in semiconductor ICs and devices calls for similar advances in semiconductor manufacturing processes and technology.
As merely one example, forming a reliable contact to a metal gate layer, and between the metal gate layer and an adjacent source, drain, and/or body region, requires a high degree of overlay control (e.g., pattern-to-pattern alignment) and a sufficiently large process window. However, with the continued scaling of IC dimensions, coupled with new patterning techniques (e.g., such as double patterning), accurate overlay control is more critical than ever. Moreover, process windows for aggressively scaled ICs are becoming quite narrow, which can lead to device degradation and/or failure. For at least some conventional processes, the process window of semiconductor fabrication processes used to form such contacts to the metal gate layer, and between the metal gate layer and an adjacent source, drain, and/or body region, has become too narrow and can no longer satisfy process window requirements.
Thus, existing techniques have not proved entirely satisfactory in all respects.